Method for manufacturing optical laminate

Abstract

A method for producing an optical laminate in which a transparent substrate, which is a plastic film, a hard coat layer, an adhesion layer, an optical functional layer, and an antifouling layer are laminated in this order, the antifouling layer having a surface roughness Ra of 3-9 nm inclusive and an optical thickness of 3-10 nm inclusive, the method comprising: a hard coat layer forming step for forming the hard coat layer; an adhesion layer forming step for forming an adhesion layer; an optical functional layer forming step for forming an optical functional layer; a surface treatment step for treating the surface of the optical functional layer; and an antifouling layer formation step for forming an antifouling layer on the surface-treated optical functional layer, the hard coat layer being composed of a binder resin and a cured product of a curable resin composition containing silica particles having an average particle diameter of 100 nm or less, and the thickness of the adhesion layer being 1-10 nm (inclusive). The antifouling layer comprises a vapor-deposited film obtained by vapor-depositing an alkoxysilane compound having a perfluoropolyether group, the surface treatment is glow discharge treatment, and the relative value of the cumulative output of the glow discharge treatment is 100-333 (inclusive) when the cumulative output is 100 at 326 Wmin / m2.

Description

[0001] This application is a divisional application of a Chinese patent application with an original application date of March 3, 2021, application number 202180017403.5, and invention title "Method for manufacturing an optical laminate". Technical Field

[0002] The present invention relates to an optical laminate having an antifouling layer on its surface, an article including the optical laminate, and a method for manufacturing the optical laminate.

[0003] This application claims priority based on Japanese Patent Application No. 2020-037146 filed in Japan on March 4, 2020, Japanese Patent Application No. 2020-123317 filed in Japan on July 17, 2020, and Japanese Patent Application No. 2021-32929 filed in Japan on March 2, 2021, the contents of which are incorporated herein by reference. Background Art

[0004] For example, in flat panel displays (FPDs), touch panels, solar cells, etc., various antireflection films for preventing reflection on the surface are used as optical laminates. Conventionally, as an antireflection film, an antireflection film having a multilayer film formed by sequentially laminating a high refractive index layer and a low refractive index layer on a transparent substrate has been proposed. On the outermost surface of such an antireflection film, an antifouling layer (surface protective layer) is usually formed for the purpose of protecting the surface and preventing fouling.

[0005] In recent years, antireflection films (optical laminates) have been widely used in touch panels of smartphones and various operating devices. Accordingly, improvement in the abrasion resistance of the optical laminate has been demanded.

[0006] For example, Patent Document 1 discloses a transparent substrate laminate in which the abrasion resistance is improved by setting the fluorine content in the constituent material of the antifouling layer within a specific range.

[0007] Patent Document 2 describes a method for forming an antifouling layer, in which at least one surface of a substrate to be treated is pretreated before forming the antifouling layer, and the antifouling layer is formed on the pretreated surface. In addition, Patent Document 2 describes that the pretreatment is any one of a high-frequency discharge plasma method, an electron beam method, an ion beam method, an evaporation method, a sputtering method, an alkali treatment method, an acid treatment method, a corona treatment method, and an atmospheric pressure glow discharge plasma method.

[0008] Patent Document 3 describes a method for manufacturing an antifouling optical article, in which an antireflection film is formed on the substrate surface by evaporation, then plasma treatment is performed by introducing oxygen or argon, and then an antifouling layer is formed by vacuum evaporation of a fluorine-containing organosilicon compound.

[0009] Prior Art Documents

[0010] Patent Document

[0011] Patent Document 1: International Publication No. WO 2019 / 078313

[0012] Patent Document 2: Japanese Patent Application Laid-Open No. 2006-175438

[0013] Patent Document 3: Japanese Patent Application Laid-Open No. 2005-301208

[0014] Patent Document 4: Japanese Patent No. 6542970 Summary of the Invention

[0015] Problems to be Solved by the Invention

[0016] However, the transparent substrate laminate described in Patent Document 1 has the following problems: If rubbed repeatedly, the unreacted substances that contribute to wear resistance will be rubbed off, and high wear resistance cannot be maintained. There is a need for an optical laminate having an antifouling layer that can maintain high wear resistance even against repeated rubbing.

[0017] The present invention has been made in view of the above problems, and an object thereof is to provide an optical laminate having an antifouling layer that can maintain high wear resistance even against repeated rubbing, an article having the optical laminate, and a method for manufacturing the optical laminate.

[0018] Means for Solving the Problems

[0019] In order to solve the above problems, the present invention provides the following means.

[0020] [1] A method for manufacturing an optical laminate according to a first aspect of the present invention is a method for manufacturing an optical laminate formed by sequentially laminating a transparent substrate, an adhesion layer, an optical functional layer, and an antifouling layer, and includes:

[0021] An adhesion layer forming step of forming an adhesion layer;

[0022] An optical functional layer forming step of forming an optical functional layer;

[0023] A surface treatment step of treating the surface of the optical functional layer such that the change rate of the surface roughness represented by the following (Formula 1) is 1 to 25%; and

[0024] An antifouling layer forming step of forming an antifouling layer on the surface-treated optical functional layer,

[0025] Change rate of surface roughness (%) = ((Ra2 / Ra1) - 1) × 100 (%)... Formula (1)

[0026] (In Formula (1), Ra1 represents the surface roughness (Ra) of the optical functional layer before surface treatment, and Ra2 represents the surface roughness (Ra) of the optical functional layer after surface treatment).

[0027] [2] The manufacturing method of the optical laminate according to the second aspect of the present invention is a manufacturing method of an optical laminate formed by sequentially laminating a transparent substrate, an adhesion layer, an optical functional layer, and an antifouling layer, including:

[0028] An adhesion layer forming step of forming an adhesion layer;

[0029] An optical functional layer forming step of forming an optical functional layer;

[0030] A surface treatment step of performing glow discharge treatment on the surface of the aforementioned optical functional layer; and

[0031] An antifouling layer forming step of forming an antifouling layer on the surface-treated aforementioned optical functional layer.

[0032] [3] In the manufacturing method of the optical laminate according to the above aspect, the aforementioned adhesion layer and the aforementioned optical functional layer can be formed by sputtering.

[0033] [4] In the manufacturing method of the optical laminate according to the above aspect, the aforementioned antifouling layer can be formed by vacuum evaporation in the aforementioned antifouling layer forming step.

[0034] [5] In the manufacturing method of the optical laminate according to the above aspect, the aforementioned adhesion layer forming step, the aforementioned optical functional layer forming step, the aforementioned surface treatment step, and the aforementioned antifouling layer forming step can be continuously performed under reduced pressure.

[0035] [6] In the manufacturing method of the optical laminate according to the above aspect, a hard coat forming step of forming a hard coat before the aforementioned adhesion layer forming step can be provided.

[0036] [7] In the manufacturing method of the optical laminate according to the above aspect, the aforementioned optical functional layer can be any one selected from an antireflection layer, a selective reflection layer, and an antiglare layer.

[0037] [8] In the manufacturing method of the optical laminate according to the above aspect, the aforementioned optical functional layer can include a low refractive index layer.

[0038] [9] In the manufacturing method of the optical laminate according to the above aspect, the aforementioned optical functional layer forming step can be a step of alternately laminating a low refractive index layer and a high refractive index layer to form a laminate.

[0039]

[10] In the manufacturing method of the optical laminate according to the above aspect, the surface of the aforementioned low refractive index layer can be treated in the aforementioned surface treatment step.

[0040]

[11] In the method for manufacturing the optical laminate according to the above-described method, the low refractive index layer may contain an oxide of Si.

[0041]

[12] The optical laminate according to the third aspect of the present invention is an optical laminate in which a transparent substrate, an adhesion layer, an optical functional layer, and an antifouling layer are sequentially laminated, and the antifouling layer is composed of a vapor deposition film on which an antifouling material is vapor deposited.

[0042]

[13] In the optical laminate according to the above-described method, the optical functional layer may be any one selected from an antireflection layer, a selective reflection layer, and an antiglare layer.

[0043]

[14] In the optical laminate according to the above-described method, the optical functional layer may include a low refractive index layer.

[0044]

[15] In the optical laminate according to the above-described method, the optical functional layer may be composed of a laminate in which a low refractive index layer and a high refractive index layer are alternately laminated.

[0045]

[16] In the optical laminate according to the above-described method, the antifouling layer may be provided in contact with the low refractive index layer.

[0046]

[17] In the optical laminate according to the above-described method, the adhesion layer may contain an oxide of Si.

[0047]

[18] In the optical laminate according to the above-described method, the antifouling material may contain a fluorine-based organic compound.

[0048]

[19] In the optical laminate according to the above-described method, a hard coat layer may be further provided between the transparent substrate and the adhesion layer.

[0049]

[20] The article according to the fourth aspect of the present invention includes the optical laminate according to the above-described method.

[0050]

[21] The method for manufacturing the optical laminate according to the fifth aspect of the present invention is the method for manufacturing the optical laminate according to the above-described method, and has an antifouling layer forming step of forming the antifouling layer composed of a vapor deposition film on which an antifouling material is vapor deposited by vacuum vapor deposition on one side of the optical functional layer.

[0051]

[22] In the method for manufacturing the optical laminate according to the above-described method, an optical functional layer forming step of forming the optical functional layer by sputtering may be included, and the optical functional layer forming step and the antifouling layer forming step may be continuously performed under reduced pressure.

[0052] Advantages of the Invention

[0053] According to the present invention, there can be provided an optical laminate having an antifouling layer that can maintain high abrasion resistance even against repeated friction, an article having the optical laminate, and a method for manufacturing the optical laminate. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 is a cross-sectional view showing an example of the optical laminate of the present embodiment.

[0055] Figure 2 is a cross-sectional view showing another example of the optical laminate of the present embodiment.

[0056] Figure 3 is a cross-sectional view showing another example of the optical laminate of the present embodiment.

[0057] Figure 4 is a schematic view showing an example of a manufacturing apparatus for explaining a method for manufacturing the optical laminate of the present embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0058] Hereinafter, the present embodiment will be described in detail with appropriate reference to the drawings. In the drawings used in the following description, in order to easily understand the features of the present invention, the characteristic parts are sometimes enlarged for convenience, and the dimensional ratios of the respective components are sometimes different from the actual ones. The materials, dimensions, etc. exemplified in the following description are examples, and the present invention is not limited thereto, and can be appropriately changed within the range in which the effects are achieved.

[0059] [Optical laminate]

[0060] Figure 1 is a cross-sectional view for explaining an example of the optical laminate of the present embodiment.

[0061] As Figure 1 shown, the optical laminate 101 of the present embodiment is formed by sequentially laminating a transparent substrate 11, an adhesion layer 13, an optical functional layer 14, and an antifouling layer 15.

[0062] The adhesion layer 13 is a layer that exhibits adhesion.

[0063] The optical functional layer 14 is a layer that exhibits an optical function. The optical function refers to a function of controlling reflection, transmission, and refraction, which are properties of light, and examples thereof include an antireflection function, a selective reflection function, an antiglare function, and a lens function.

[0064] The optical functional layer 14 is preferably any one selected from an antireflection layer, a selective reflection layer, and an antiglare layer. As the antireflection layer, the selective reflection layer, and the antiglare layer, known layers can be used. The antireflection layer, the selective reflection layer, and the antiglare layer can each be a single layer or a multilayer laminate. ​​​​

[0065] Figure 2 This is a cross-sectional view showing another example of the optical laminate of the present embodiment.

[0066] Figure 2 The optical laminate 102 shown is formed by sequentially laminating a transparent substrate 11, a hard coat 12, an adhesion layer 13, an optical functional layer 14, and an antifouling layer 15.

[0067] The adhesion layer 13 is a layer that exhibits adhesion.

[0068] The optical functional layer 14 is a layer that exhibits optical functions. Optical functions refer to functions that control reflection, transmission, and refraction, which are properties of light. Examples include an antireflection function, a selective reflection function, an antiglare function, a lens function, etc.

[0069] The optical functional layer 14 is preferably any one selected from an antireflection layer, a selective reflection layer, and an antiglare layer. As the antireflection layer, selective reflection layer, and antiglare layer, known layers can be used. The antireflection layer, selective reflection layer, and antiglare layer can each be a single layer or a multilayer laminate.

[0070] Figure 3 This is a cross-sectional view showing another example of the optical laminate of the present embodiment.

[0071] Figure 3 In the optical laminate 101 shown, as Figure 2 In the optical functional layer 14 of the optical laminate 102 shown, an antireflection layer is provided. The optical functional layer 14 (antireflection layer) is, as Figure 2 shown, composed of a laminate formed by alternately laminating a low refractive index layer 14b and a high refractive index layer 14a. Figure 2 The optical functional layer 14 shown is sequentially laminated with a hard coat 12, an adhesion layer 13, a high refractive index layer 14a, a low refractive index layer 14b, a high refractive index layer 14a, a low refractive index layer 14b, and an antifouling layer 15 from the side of the transparent substrate 11. Therefore, the antifouling layer 15 is in contact with the low refractive index layer 14b of the optical functional layer 14.

[0072] The transparent substrate 11 may be formed of a transparent material that can transmit light in the visible light region. For example, a plastic film is preferably used. Specific examples of the constituent material of the plastic film include polyester resins, acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, and polyphenylene sulfide resins.

[0073] It should be noted that the "transparent material" in the present invention refers to a material with a light transmittance of 80% or more in the wavelength region used within the range that does not impair the effects of the present invention.

[0074] In addition, in the present embodiment, "(meth)acrylic acid" refers to methacrylic acid and acrylic acid.

[0075] As long as the optical properties are not significantly impaired, the transparent substrate 11 may contain a reinforcing material, such as cellulose nanofibers, nano-silica, etc. In particular, polyester-based resins, acetate-based resins, polycarbonate-based resins, and polyolefin-based resins are preferably used. Specifically, a triacetyl cellulose (TAC) substrate is preferably used.

[0076] In addition, as the inorganic substrate, a glass film can also be used.

[0077] When the plastic film is a TAC substrate and a hard coat 12 is formed on one side thereof, a penetration layer in which a part of the components constituting the hard coat 12 penetrates can be formed. As a result, the adhesion between the transparent substrate 11 and the hard coat 12 becomes good, and the generation of interference fringes caused by the refractive index difference between the layers can be suppressed.

[0078] The transparent substrate 11 may also be a film provided with an optical function and / or a physical function. Examples of the film having an optical and / or physical function include a polarizing plate, a retardation compensation film, a heat ray blocking film, a transparent conductive film, a brightness enhancement film, and a barrier property enhancement film.

[0079] The thickness of the transparent substrate 11 is not particularly limited, and is preferably 25 μm or more, for example. The film thickness of the transparent substrate 11 is more preferably 40 μm or more.

[0080] If the thickness of the transparent substrate 11 is 25 μm or more, the rigidity of the substrate itself can be ensured, and even if stress is applied to the optical laminate 10, wrinkles are not easily generated. In addition, if the thickness of the transparent substrate 11 is 25 μm or more, even if the hard coat 12 is continuously formed on the transparent substrate 11, wrinkles are not easily generated, and there are few concerns in manufacturing, which is preferable. If the thickness of the transparent substrate 11 is 40 μm or more, wrinkles are less likely to be generated, which is preferable.

[0081] When it is carried out using rollers during manufacturing, the thickness of the transparent substrate 11 is preferably 1,000 μm or less, more preferably 600 μm or less. If the thickness of the transparent substrate 11 is 1,000 μm or less, it is easy to wind the optical laminate 10 during manufacturing and the manufactured optical laminate 10 into a roll shape, and the optical laminate 10 can be manufactured efficiently. In addition, if the thickness of the transparent substrate 11 is 1,000 μm or less, it is possible to thin and lighten the optical laminate 10. If the thickness of the transparent substrate 11 is 600 μm or less, the optical laminate 10 can be manufactured more efficiently, and further thinning and lightening can be achieved, which is preferable.

[0082] The transparent substrate 11 may also be subjected to etching treatment such as sputtering, corona discharge, ultraviolet irradiation, electron beam irradiation, chemical conversion, oxidation, etc. and / or primer treatment on the surface in advance. By performing these treatments in advance, the adhesion to the hard coat 12 formed on the transparent substrate 11 can be improved. In addition, it is also preferable to perform solvent cleaning, ultrasonic cleaning, etc. on the surface of the transparent substrate 11 as needed before forming the hard coat 12 on the transparent substrate 11, thereby removing dust and purifying the surface of the transparent substrate 11 in advance.

[0083] As the hard coat 12, a known hard coat can be used. The hard coat 12 may be composed only of an adhesive resin, or may contain a filler within a range that does not impair transparency together with the adhesive resin. As the filler, a filler composed of an organic substance, a filler composed of an inorganic substance, or a filler composed of an organic substance and an inorganic substance can be used.

[0084] As the adhesive resin used in the hard coat 12, a transparent adhesive resin is preferable. For example, a resin curable by ultraviolet rays or electron beams, that is, an ionizing radiation curable resin, a thermoplastic resin, a thermosetting resin, etc. can be used.

[0085] Examples of the ionizing radiation curable resin used in the adhesive resin of the hard coat 12 include ethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, styrene, methylstyrene, N-vinylpyrrolidone, etc.

[0086] In addition, as a compound which is a radiation-curable resin having two or more unsaturated bonds, examples thereof include trimethylolpropane tri(meth)acrylate, tripropylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, bis-trimethylolpropane tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, tripentaerythritol octa(meth)acrylate, tetrapentaerythritol deca(meth)acrylate, isocyanuric acid tri(meth)acrylate, isocyanuric acid di(meth)acrylate, polyester tri(meth)acrylate, polyester di(meth)acrylate, bisphenol di(meth)acrylate, diglycerol tetra(meth)acrylate, adamantyl di(meth)acrylate, isobornyl di(meth)acrylate, dicyclopentane di(meth)acrylate, tricyclodecane di(meth)acrylate, bis-trimethylolpropane tetra(meth)acrylate and other polyfunctional compounds. Among them, pentaerythritol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA) and pentaerythritol tetraacrylate (PETTA) are preferably used. It should be noted that "(meth)acrylate" means methacrylate and acrylate. In addition, as the radiation-curable resin, a substance obtained by modifying the above compound with PO (propylene oxide), EO (ethylene oxide), CL (caprolactone) or the like can also be used.

[0087] As the thermoplastic resin used in the binder resin of the hard coat 12, examples thereof include styrene resins, (meth)acrylic resins, vinyl acetate resins, vinyl ether resins, halogen-containing resins, alicyclic olefin resins, polycarbonate resins, polyester resins, polyamide resins, cellulose derivatives, silicone resins, rubbers or elastomers. The above thermoplastic resin is preferably non-crystalline and soluble in an organic solvent (especially a common solvent capable of dissolving a plurality of polymers and curable compounds). In particular, from the viewpoints of transparency and weather resistance, styrene resins, (meth)acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (such as cellulose esters) and the like are preferred.

[0088] As the thermosetting resin used in the binder resin of the hard coat 12, examples thereof include phenolic resins, urea resins, diallyl phthalate resins, melamine resins, guanamine resins, unsaturated polyester resins, polyurethane resins, epoxy resins, amino alkyd resins, melamine-urea co-condensation resins, silicone resins, polysiloxane resins (including so-called silsesquioxanes such as cage-shaped and ladder-shaped ones) and the like.

[0089] The hard coat 12 may contain an organic resin and an inorganic material, or may be an organic-inorganic hybrid material. As an example, an example formed by the sol-gel method can be cited. As the inorganic material, for example, silica, alumina, zirconia, and titanium dioxide can be cited. As the organic material, for example, an acrylic resin can be cited.

[0090] From the viewpoints of antiglare property, adhesion to the optical functional layer 14 described later, and anti-blocking property, various fillers can be selected for the filler contained in the hard coat 12 according to the use of the optical laminate 10. Specifically, for example, known particles such as silica (oxide of Si) particles, alumina (aluminum oxide) particles, and organic fine particles can be used.

[0091] The hard coat 12 may contain, for example, a binder resin and silica particles and / or alumina particles as fillers. By dispersing silica particles and / or alumina particles as fillers in the hard coat 12, fine irregularities can be formed on the surface of the hard coat 12. These silica particles and / or alumina particles may be exposed on the surface of the hard coat 12 on the side of the optical functional layer 14. In this case, the binder resin of the hard coat 12 and the optical functional layer 14 are firmly joined. Therefore, the adhesion between the hard coat 12 and the optical functional layer 14 is improved, the hardness of the hard coat 12 becomes high, and the scratch resistance of the optical laminate 10 becomes good.

[0092] The average particle diameter of the silica particles and / or alumina particles as the filler of the hard coat 12 is, for example, 800 nm or less, preferably 780 nm or less, and more preferably 100 nm or less.

[0093] From the viewpoint of improving the antiglare property of the optical laminate 10, organic fine particles can be used as the filler contained in the hard coat 12. As the organic fine particles, for example, an acrylic resin can be cited. The particle diameter of the organic fine particles is preferably 10 μm or less, more preferably 5 μm or less, and particularly preferably 3 μm or less.

[0094] As the filler contained in the hard coat 12, various reinforcing materials can be used within a range that does not impair the optical properties in order to impart toughness to the hard coat 12. As the reinforcing material, for example, cellulose nanofibers can be cited.

[0095] The thickness of the hard coat 12 is not particularly limited. For example, it is preferably 0.5 μm or more, more preferably 1 μm or more. The thickness of the hard coat 12 is preferably 100 μm or less. When the thickness of the hard coat 12 is 0.5 μm or more, sufficient hardness can be obtained, so scratches are not easily generated during manufacturing. In addition, when the thickness of the hard coat 12 is 100 μm or less, thinning and weight reduction of the optical laminate 10 can be achieved. In addition, when the thickness of the hard coat 12 is 100 μm or less, microcracks of the hard coat 12 generated when the optical laminate 10 is bent during manufacturing are not easily generated, and the productivity becomes good.

[0096] The hard coat 12 may be a single layer or a layer formed by laminating multiple layers. In addition, known functions such as ultraviolet absorption performance, antistatic performance, refractive index adjustment function, and hardness adjustment function may be further imparted to the hard coat 12.

[0097] In addition, the functions imparted to the hard coat 12 may be imparted in a single hard coat or may be divided into multiple layers and imparted.

[0098] The adhesion layer 13 is a layer formed to ensure good adhesion between the transparent substrate 11 or the hard coat 12, which is an organic film, and the optical functional layer 14, which is an inorganic film. In the Figure 3 shown optical laminate 10, an adhesion layer 13 is provided between the hard coat 12 and the optical functional layer 14. The adhesion layer 13 has a function of adhering the hard coat 12 and the optical functional layer 14. The adhesion layer 13 is preferably composed of a metal oxide or a metal in an oxygen-deficient state. The metal oxide in an oxygen-deficient state refers to a metal oxide in a state where the number of oxygen atoms is insufficient compared to the stoichiometric composition. Examples of the metal oxide in an oxygen-deficient state include SiOx, ALOx, TiOx, ZrOx, CeOx, MgOx, ZnOx, TaOx, SbOx, SnOx, MnOx, etc. In addition, examples of the metal include Si, Al, Ti, Zr, Ce, Mg, Zn, Ta, Sb, Sn, Mn, In, etc. The adhesion layer 13 may be, for example, a layer in which x in SiOx exceeds 0 and is less than 2.0. In addition, the adhesion layer may be formed of a mixture of multiple metals or metal oxides.

[0099] From the viewpoints of maintaining transparency and adhesion to the optical functional layer and obtaining good optical characteristics, the thickness of the adhesion layer is preferably more than 0 nm and 20 nm or less, particularly preferably 1 nm or more and 10 nm or less.

[0100] The optical functional layer 14 is a laminate that exhibits an antireflection function. Figure 3The optical functional layer 14 shown is a laminate of a total of four layers formed by alternately laminating a high refractive index layer 14a and a low refractive index layer 14b in order from the adhesion layer 13 side. The number of layers of the high refractive index layer 14a and the low refractive index layer 14b is not particularly limited, and the number of layers of the high refractive index layer 14a and the low refractive index layer 14b can be set to any number.

[0101] In Figure 3 In the optical laminate 10 shown, the optical functional layer 14 is composed of a laminate formed by alternately laminating a low refractive index layer 14b and a high refractive index layer 14a. Therefore, light incident from the antifouling layer 15 side is diffused by the optical functional layer 14. Therefore, an antireflection function that prevents light incident from the antifouling layer 15 side from being reflected in one direction can be obtained.

[0102] From the viewpoints of ease of acquisition and cost, the low refractive index layer 14b preferably contains an oxide of Si, and is preferably a layer mainly composed of SiO 2 (oxide of Si), etc. SiO 2 The single-layer film is colorless and transparent. In the present embodiment, the main component of the low refractive index layer 14b means a component contained in the low refractive index layer 14b in an amount of 50% by mass or more.

[0103] When the low refractive index layer 14b is a layer mainly composed of an oxide of Si, other elements in an amount less than 50% by mass may also be contained. The content of elements different from the oxide of Si is preferably 10% or less. As other elements, for example, for the purpose of improving durability, Na may be contained, and for the purpose of improving hardness, Zr, Al, and N may be contained, and for the purpose of improving alkali resistance, Zr and Al may be contained.

[0104] The refractive index of the low refractive index layer 14b is preferably 1.20 to 1.60, more preferably 1.30 to 1.50. As the dielectric used in the low refractive index layer 14b, magnesium fluoride (MgF 2 , refractive index 1.38), etc. can be cited.

[0105] The refractive index of the high refractive index layer 14a is preferably 2.00 to 2.60, more preferably 2.10 to 2.45. As the dielectric used in the high refractive index layer 14a, niobium pentoxide (Nb 2 O 5 , refractive index 2.33), titanium oxide (TiO 2 , refractive index 2.33 to 2.55), tungsten oxide (WO 3 , refractive index 2.2), cerium oxide (CeO 2 , refractive index 2.2), tantalum pentoxide (Ta 2 O 5, refractive index 2.16), zinc oxide (ZnO, refractive index 2.1), indium tin oxide (ITO, refractive index 2.06), zirconium oxide (ZrO 2 , refractive index 2.2), etc.

[0106] When it is desired to impart electrical conductivity to the high refractive index layer 14a, for example, ITO or indium zinc oxide (IZO) can be selected.

[0107] The optical functional layer 14 is preferably formed, for example, of a layer composed of niobium pentoxide (Nb 2 O 5 , refractive index 2.33) as the high refractive index layer 14a, and a layer composed of SiO 2 as the low refractive index layer 14b.

[0108] The film thickness of the low refractive index layer 14b only needs to be in the range of 1 nm or more and 200 nm or less, and can be appropriately selected according to the wavelength region of the antireflection function required.

[0109] The film thickness of the high refractive index layer 14a only needs to be, for example, 1 nm or more and 200 nm or less, and can be appropriately selected according to the wavelength region of the antireflection function required.

[0110] The film thicknesses of the high refractive index layer 14a and the low refractive index layer 14b can be appropriately selected according to the design of the optical functional layer 14, respectively.

[0111] For example, starting from the adhesion layer 13 side, a high refractive index layer 14a of 5 to 50 nm, a low refractive index layer 14b of 10 to 80 nm, a high refractive index layer 14a of 20 to 200 nm, and a low refractive index layer 14b of 50 to 200 nm can be provided in sequence.

[0112] In the layer where the optical functional layer 14 is formed, the low refractive index layer 14b is disposed on the antifouling layer 15 side. When the low refractive index layer 14b of the optical functional layer 14 is in contact with the antifouling layer 15, the antireflection performance of the optical functional layer 14 becomes good, and thus it is preferable.

[0113] The antifouling layer 15 is formed on the outermost surface of the optical functional layer 14 to prevent the optical functional layer 14 from being soiled. In addition, when applied to a touch panel or the like, the antifouling layer 15 suppresses the loss of the optical functional layer 14 due to abrasion resistance.

[0114] The antifouling layer 15 of the present embodiment is composed of a vapor deposition film on which an antifouling material is vapor-deposited. In the present embodiment, the antifouling layer 15 is formed by vacuum vapor-depositing a fluorine-based organic compound as the antifouling material on one surface of the low refractive index layer 14b constituting the optical functional layer 14. In the present embodiment, since the antifouling material contains a fluorine-based organic compound, the optical laminate 10 has better friction resistance and alkali resistance.

[0115] As the fluorine-based organic compound constituting the antifouling layer 15, a compound composed of a fluorine-modified organic group and a reactive silyl group (such as alkoxysilane) is preferably used. As commercially available products, Optool DSX (manufactured by Daikin Industries, Ltd.), KY-100 series (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like can be cited.

[0116] As the fluorine-based organic compound constituting the antifouling layer 15, a compound composed of a fluorine-modified organic group and a reactive silyl group (such as alkoxysilane) is used as the fluorine-based organic compound, and a layer composed of SiO 2 When the low refractive index layer 14b of the optical functional layer 14 in contact with the antifouling layer 15 is formed, a siloxane bond is formed between the silanol group as the skeleton of the fluorine-based organic compound and SiO 2 Therefore, it is preferable that the adhesion between the optical functional layer 14 and the antifouling layer 15 becomes good.

[0117] The optical thickness of the antifouling layer 15 may be in the range of 1 nm or more and 20 nm or less, preferably in the range of 3 nm or more and 10 nm or less. If the thickness of the antifouling layer 15 is 1 nm or more, sufficient abrasion resistance can be ensured when the optical laminate 10 is applied to touch panel applications and the like. In addition, if the thickness of the antifouling layer 15 is 20 nm or less, the time required for evaporation deposition can be within a short time, and manufacturing can be performed efficiently.

[0118] The surface roughness Ra of the antifouling layer 15 varies depending on the use and configuration of the optical laminate. For example, in the case of a transparent antireflection layer without an antiglare function, it is preferably 3 nm or more. The upper limit is not particularly limited. For example, from the viewpoint of scratch resistance, it is preferably 9 nm or less.

[0119] The antifouling layer 15 may contain additives such as a light stabilizer, an ultraviolet absorber, a colorant, an antistatic agent, a lubricant, a leveling agent, a defoaming agent, an antioxidant, a flame retardant, an infrared absorber, and a surfactant as needed.

[0120] The antifouling layer 15 formed by evaporation deposition is firmly bonded to the optical functional layer 14, has few voids, and is dense. Thus, the antifouling layer 15 of the present embodiment exhibits characteristics different from those of the antifouling layer formed by a conventional method such as coating with an antifouling material.

[0121] For example, the antifouling layer 15 of the optical laminate 10 of the present embodiment has the following characteristics.

[0122] (1) The contact angle difference with respect to water after a scratch test by horizontally reciprocating steel wool 500 times is 10° or less.

[0123] (2) The contact angle with respect to water is 110° or more after the abrasion test by horizontally reciprocating the steel wool 500 times.

[0124] (3) The contact angle with respect to water is 100° or more after the abrasion test by reciprocating the cloth (non-woven fabric wiper) 4000 times.

[0125] (4) The change amount (ΔE value) of the L*a*b* values shown in the following formula (2) based on SCI (Specular Component Include, a measurement method considering the reflected color of the specularly reflected light) before and after the abrasion test by horizontally reciprocating the steel wool 500 times is 3.0 or less.

[0126] [Equation 1]

[0127]

[0128] (In formula (2), L0 * , a0 * , b0 * are the values before the abrasion test, and L1 * , a1 * , b1 * are the values after the abrasion test.)

[0129] (5) The change amount (ΔE value) of the L*a*b* values shown in the following formula (3) based on SCE (Specular Component Exclude, a measurement method not considering the reflected color of the specularly reflected light) before and after the abrasion test by horizontally reciprocating the steel wool 500 times is 1.5 or less.

[0130] [Equation 2]

[0131]

[0132] (In formula (3), L0 * , a0 * , b0 * are the values before the abrasion test, and L1 * , a1 * , b1 * are the values after the abrasion test.)

[0133] (6) The fluorine residual rate measured by the fluorescence X-ray analysis method (XRF) after immersion in a 0.1 mol / L NaOH solution (liquid temperature 55°C) for 4 hours is 70% or more.

[0134] The optical laminate 10 having the antifouling layer 15 formed by vapor deposition according to the present embodiment has fewer voids and is formed densely compared to the antifouling layer formed by coating. Further, in the optical laminate 10 of the present embodiment, the antifouling layer 15 is firmly bonded to the low refractive index layer 14b in contact with the antifouling layer 15. Therefore, the optical laminate 10 of the present embodiment has excellent visible light transmittance, can maintain high abrasion resistance against repeated rubbing, and can also maintain high resistance to alkalinity.

[0135] [Method for manufacturing an optical laminate]

[0136] Figure 3 The optical laminate 10 of the present embodiment shown, for example, can be manufactured by the method shown below.

[0137] In the present embodiment, as an example of the method for manufacturing the optical laminate 10, the case of manufacturing the optical laminate 10 using the transparent substrate 11 wound in a roll shape will be described.

[0138] First, the transparent substrate 11 wound in a roll shape is unwound. Then, a slurry containing a material for forming the hard coat 12 is coated on the transparent substrate 11 by a known method, and is cured by a known method corresponding to the material for forming the hard coat 12. Thereby, the hard coat 12 is formed (hard coat forming step). Then, the transparent substrate 11 having the hard coat 12 formed on the surface is wound into a roll shape by a known method.

[0139] Next, an adhesion layer forming step of forming the adhesion layer 13 on the hard coat 12 and an optical functional layer forming step of forming the optical functional layer 14 are performed. Then, an antifouling layer forming step of forming the antifouling layer 15 on the optical functional layer 14 is performed. In the present embodiment, it is preferable to perform a first surface treatment step of treating the surface of the hard coat 12 before the optical functional layer forming step, and then perform the adhesion layer forming step and the optical functional layer forming step. Further, in the present embodiment, it is preferable to perform a second surface treatment step of treating the surface of the antireflection film after the optical functional layer forming step, and then perform the antifouling layer forming step.

[0140] In the method for manufacturing the optical laminate 10 of the present embodiment, it is preferable that the first surface treatment step, the adhesion layer forming step, the optical functional layer forming step, the second surface treatment step, and the antifouling layer forming step are continuously performed while maintaining the optical laminate during manufacturing under a reduced pressure state. When the first surface treatment step, the adhesion layer forming step, the optical functional layer forming step, the second surface treatment step, and the antifouling layer forming step are continuously performed while maintaining the optical laminate during manufacturing under a reduced pressure state, for example, as a sputtering device, a device having a thin film forming device described in Patent Document 4 can be used.

[0141] As a manufacturing apparatus for the manufacturing method of the optical laminate that can be used in the present embodiment, specifically, the manufacturing apparatus 20 shown in Figure 4 can be cited.

[0142] Figure 4 The manufacturing apparatus 20 shown in Figure 4 is equipped with a roll unwinding device 4, a pretreatment device 2A, a sputtering device 1, a pretreatment device 2B, an evaporation device 3, and a roll winding device 5. As shown in Figure 4 these devices 4, 2A, 1, 2B, 3, 5 are connected in sequence. Figure 4 The manufacturing apparatus 20 shown in Figure 4 is a roll-to-roll type manufacturing apparatus, that is: by unwinding the substrate from the roll, after the connected devices (in Figure 4 are the pretreatment device 2A, the sputtering device 1, the pretreatment device 2B, and the evaporation device 3) continuously pass through, it is wound up, so that multiple layers are continuously formed on the substrate.

[0143] When manufacturing the optical laminate 10 using a roll-to-roll type manufacturing apparatus, the conveying speed (linear speed) of the optical laminate 10 during manufacturing can be appropriately set. The conveying speed is preferably set to 0.5 to 20 m / min, and more preferably set to 0.5 to 10 m / min.

[0144] <Roll unwinding device>

[0145] Figure 4 The roll unwinding device 4 shown in Figure 4 has: a chamber 34, the inside of which becomes a prescribed reduced-pressure atmosphere; one or more vacuum pumps 21 (in Figure 4 is one), which discharges the gas in the chamber 34 to become a reduced-pressure atmosphere; and an unwinding roll 23 and a guide roll 22, which are provided inside the chamber 34. As shown in Figure 4 the chamber 34 is connected to the chamber 31 of the sputtering device 1.

[0146] On the unwinding roll 23, a transparent substrate 11 formed with a hard coat 12 is wound around the surface. The unwinding roll 23 supplies the transparent substrate 11 formed with a hard coat 12 on the surface to the pretreatment device 2A at a prescribed conveying speed.

[0147] <Pretreatment device 2A>

[0148] Figure 4 The pretreatment device 2A shown in Figure 4 has a chamber 32 the inside of which becomes a prescribed reduced-pressure atmosphere, a can-shaped roll 26, a plurality of (in Figure 4 are two) guide rolls 22, and a plasma discharge device 42. As shown in Figure 4 the can-shaped roll 26, the guide roll 22, and the plasma discharge device 42 are provided inside the chamber 32. As shown in Figure 4 the chamber 32 is connected to the chamber 31 of the sputtering device 1.

[0149] The can-shaped roller 26 and the guide roller 22 convey the transparent substrate 11 formed with the hard coating 12 sent out from the roll feeding device 4 at a prescribed conveying speed, and send out the transparent substrate 11 whose surface of the hard coating 12 has been treated to the sputtering device 1.

[0150] As Figure 4 shown, the plasma discharge device 42 is disposed opposite to the outer peripheral surface of the can-shaped roller 26 with a prescribed interval therebetween. The plasma discharge device 42 ionizes the gas by glow discharge. As the gas, a gas that is inexpensive, inactive, and does not affect the optical characteristics is preferable, and for example, argon, oxygen, nitrogen, helium, etc. can be used. As the gas, argon is preferably used because it has a large mass, is chemically stable, and is easily obtained.

[0151] In the present embodiment, as the plasma discharge device 42, a glow discharge device that ionizes argon using high-frequency plasma is preferably used.

[0152] <Sputtering device>

[0153] Figure 4 The sputtering device 1 shown has: a chamber 31 whose interior becomes a prescribed reduced-pressure atmosphere; one or more vacuum pumps 21 (two in Figure 4 this case) that discharge the gas in the chamber 31 to become a reduced-pressure atmosphere; a film-forming roller 25; a plurality of (two in Figure 4 this case) guide rollers 22; and a plurality of (four in the example shown in Figure 4 this case) film-forming parts 41. As Figure 4 shown, the film-forming roller 25, the guide rollers 22, and the film-forming parts 41 are disposed in the chamber 31. As Figure 4 shown, the chamber 31 is connected to the chamber 32 of the pretreatment device 2B.

[0154] The film-forming roller 25 and the guide rollers 22 convey the transparent substrate 11 formed with the surface-treated hard coating 12 sent out from the pretreatment device 2A at a prescribed conveying speed, and supply the transparent substrate 11 formed with the adhesion layer 13 and the optical functional layer 14 on the hard coating 12 to the pretreatment device 2B.

[0155] In Figure 4 the sputtering device 1 shown, on the hard coating 12 of the transparent substrate 11 moving on the film-forming roller 25, the adhesion layer 13 is laminated by sputtering, and the high refractive index layer 14a and the low refractive index layer 14b are alternately laminated thereon to form the optical functional layer 14.

[0156] As Figure 4As shown, the film forming section 41 is disposed opposite to the outer peripheral surface of the film forming roll 25 with a predetermined interval therebetween, and a plurality of film forming sections 41 are provided so as to surround the film forming roll 25. The number of film forming sections 41 is determined according to the total number of stacked layers of the adhesion layer 13 and the high refractive index layer 14a and the low refractive index layer 14b forming the optical functional layer 14. When it is difficult to ensure the distance between adjacent film forming sections 41 due to the large total number of stacked layers of the adhesion layer 13 and the high refractive index layer 14a and the low refractive index layer 14b forming the optical functional layer 14, a plurality of film forming rolls 25 may be provided in the chamber 31, and the film forming sections 41 may be disposed around each film forming roll 25. When a plurality of film forming rolls 25 are provided, guide rolls 22 may be provided as needed. The chambers 31 provided with the film forming rolls 25 and the film forming sections 41 may be connected in multiple units. In addition, in order to easily ensure the distance between adjacent film forming sections 41, the diameter of the film forming roll 25 may be appropriately changed.

[0157] A predetermined target (not shown) is provided in each film forming section 41. A voltage is applied to the target by a known structure. In the present embodiment, a gas supply section (not shown) for supplying a predetermined reactive gas and a carrier gas to the target at a predetermined flow rate and a known magnetic field generation source (not shown) for forming a magnetic field on the surface of the target are provided near the target.

[0158] The type and flow rate of the target material and the reactive gas can be appropriately determined according to the composition of the adhesion layer 13, the high refractive index layer 14a, and the low refractive index layer 14b formed on the transparent substrate 11 by passing between the film forming section 41 and the film forming roll 25. For example, when forming a layer composed of SiO 2 Si is used as the target and O 2 is used as the reactive gas. In addition, for example, when forming a layer composed of Nb 2 O 5 Nb is used as the target and O 2 is used as the reactive gas.

[0159] In the present embodiment, from the viewpoint of increasing the film forming speed, as the sputtering method, a magnetron sputtering method is preferably used.

[0160] In addition, the sputtering method is not limited to the magnetron sputtering method, and a two-pole sputtering method using direct current glow discharge or plasma generated by high frequency, a three-pole sputtering method with a heated cathode, etc. may also be used.

[0161] The sputtering apparatus 1 includes an optical monitor (not shown) as a measurement section, and this measurement section measures the optical characteristics after forming each layer of the adhesion layer 13 and the optical functional layer 14. Thereby, the quality of the formed adhesion layer 13 and optical functional layer 14 can be confirmed. When the sputtering apparatus 1 has, for example, two or more chambers, it is preferable to provide an optical monitor in each chamber.

[0162] As an optical monitor (not shown), for example, an optical monitor can be cited that measures the optical characteristics in the width direction of the adhesion layer 13 and the optical functional layer 14 formed on the hard coat 12 using an optical head capable of scanning in the width direction. In the case of having such an optical monitor, for example, as the optical characteristics, the peak wavelength of the reflectance is measured and converted into the optical thickness, whereby the optical thickness distribution in the width direction of the adhesion layer 13 and the optical functional layer 14 can be measured. By using the optical monitor to measure the optical characteristics, the sputtering conditions can be adjusted in real time, and the optical laminate 10 having the adhesion layer 13 and the optical functional layer 14 with the optimal optical characteristics can be formed.

[0163] <Pretreatment device 2B>

[0164] Figure 4 The shown pretreatment device 2B has a chamber 32 with a prescribed reduced-pressure atmosphere inside, a can-shaped roller 26, a plurality of (two in Figure 4 this case) guide rollers 22, and a plasma discharge device 42. As Figure 4 shown, the can-shaped roller 26, the guide rollers 22, and the plasma discharge device 42 are provided inside the chamber 32. As Figure 4 shown, the chamber 32 is connected to the chamber 33 of the evaporation device 3.

[0165] The can-shaped roller 26 and the guide rollers 22 convey the transparent substrate 11 formed with each layer up to the optical functional layer 14 sent out from the sputtering device 1 at a prescribed conveying speed, and send out the transparent substrate 11 whose surface of the optical functional layer 14 has been treated to the evaporation device 3.

[0166] As the plasma discharge device 42, for example, the same device as the pretreatment device 2A can be used.

[0167] <Evaporation device>

[0168] Figure 4 The shown evaporation device 3 has: a chamber 33 with a prescribed reduced-pressure atmosphere inside; one or more vacuum pumps 21 (one in Figure 4 this case) for discharging the gas inside the chamber 33 to form a reduced-pressure atmosphere; a plurality of (four in Figure 4 this case) guide rollers 22; an evaporation source 43; and a heating device 53. As Figure 4 shown, the guide rollers 22 and the evaporation source 43 are provided inside the chamber 33. The chamber 33 is connected to the chamber 35 of the roll winding device 5.

[0169] The evaporation source 43 is disposed opposite to the surface-treated transparent substrate 11 of the optical functional layer 14 that is conveyed substantially horizontally between two adjacent guide rollers 22. The evaporation source 43 supplies evaporation gas composed of the material for forming the antifouling layer 15 onto the optical functional layer 14. The orientation of the evaporation source 43 can be arbitrarily set.

[0170] The heating device 53 heats the material for forming the antifouling layer 15 to the vapor pressure temperature. As the heating device 53, a device that heats by means of resistance heating, heater heating, induction heating, electron beam heating, etc. can be used. In the resistance heating method, the container that houses the antifouling material for forming the antifouling layer 15 is used as a resistor and is electrically heated. In the heater heating method, the container is heated by a heater disposed on the outer periphery of the container. In the induction heating method, the container or the antifouling material is heated from an induction coil provided outside through electromagnetic induction.

[0171] Figure 4 The evaporation device 3 shown includes a guide plate (not shown) that guides the evaporation material evaporated from the evaporation source 43 to a specified position, a film thickness gauge (not shown) that observes the thickness of the antifouling layer 15 formed by evaporation, a vacuum pressure gauge (not shown) that measures the pressure inside the chamber 33, and a power supply device (not shown).

[0172] The guide plate can be of any shape as long as it can guide the evaporated evaporation material to the desired position. The guide plate may not be provided if not needed.

[0173] As the vacuum pressure gauge, an ion gauge, etc. can be used, for example.

[0174] As the power supply device, a high-frequency power supply, etc. can be cited, for example.

[0175] <Roll winding device>

[0176] Figure 4 The roll winding device 5 shown has: a chamber 35, the inside of which becomes a specified reduced-pressure atmosphere; one or more vacuum pumps 21 (one in Figure 4 this case), which discharge the gas inside the chamber 35 to form a reduced-pressure atmosphere; a winding roll 24 and guide rollers 22, which are provided inside the chamber 35.

[0177] The transparent substrate 11 (optical laminate 10) having each layer formed up to the antifouling layer 15 on its surface is wound around the winding roll 24. The winding roll 24 and the guide rollers 22 wind the optical laminate 10 at a specified winding speed.

[0178] A carrier film can also be used as needed.

[0179] As Figure 4The vacuum pump 21 included in the manufacturing apparatus 20 shown can be, for example, a dry pump, an oil rotary pump, a turbo molecular pump, an oil diffusion pump, a cryopump, a sputter pump, a getter pump, or the like. In each of the chambers 31, 32, 33, 34, 35, the vacuum pump 21 can be appropriately selected or used in combination to form a desired reduced-pressure state.

[0180] The vacuum pump 21 only needs to be able to maintain both the chamber 31 of the sputtering apparatus 1 and the chamber 33 of the vapor deposition apparatus 3 in a desired reduced-pressure state, and there are no particular limitations on the installation position and number of the vacuum pump 21 in the manufacturing apparatus 20. Additionally, in Figure 4 the manufacturing apparatus 20 shown, the roll unwinding device 4, the pretreatment device 2A, the sputtering apparatus 1, the pretreatment device 2B, the vapor deposition apparatus 3, and the roll winding device 5 are connected. Therefore, the vacuum pump 21 can be respectively provided in the chambers 31, 32, 33, 34, 35, or it can also be provided only in a part of the chambers 31, 32, 33, 34, 35 as long as it can maintain both the chamber 31 of the sputtering apparatus 1 and the chamber 33 of the vapor deposition apparatus 3 in a desired reduced-pressure state.

[0181] Next, using Figure 4 the manufacturing apparatus 20 shown, a method of continuously performing a first surface treatment process, a bonding layer formation process, an optical functional layer formation process, a second surface treatment process, and an antifouling layer formation process while maintaining the optical laminate 10 during manufacturing in a reduced-pressure state will be described.

[0182] First, in the chamber 34 of the roll unwinding device 4, a unwind roll 23 around which a transparent substrate 11 having a hard coat 12 formed on its surface is wound is provided. Then, the unwind roll 23 and the guide roll 22 are rotated, and the transparent substrate 11 having the hard coat 12 formed on its surface is sent to the pretreatment device 2A at a predetermined conveyance speed.

[0183] Next, in the chamber 32 of the pretreatment device 2A, as a pretreatment of the surface for forming the bonding layer 13 and the optical functional layer 14, a first surface treatment process is performed. In the present embodiment, the first surface treatment process is performed on the transparent substrate 11 having the hard coat 12 formed thereon.

[0184] In the first surface treatment process, the can-shaped roll 26 and the guide roll 22 are rotated, and while the transparent substrate 11 having the hard coat 12 formed thereon is conveyed at a predetermined conveyance speed, the surface of the hard coat 12 moving on the can-shaped roll 26 is treated.

[0185] As a surface treatment method for the hard coat 12, for example, glow discharge treatment, plasma treatment, ion etching, alkali treatment, etc. can be used. Among them, glow discharge treatment is preferably used because large-area treatment can be performed. The glow discharge treatment can be performed, for example, at a treatment intensity of 0.1 to 10 kwh.

[0186] By performing glow discharge treatment on the surface of the hard coat 12, the surface of the hard coat 12 is roughened at the nanoscale, and substances with weak bonding force existing on the surface of the hard coat 12 are removed. As a result, the adhesion between the hard coat 12 and the optical functional layer 14 formed on the hard coat 12 becomes good.

[0187] Next, an adhesion layer forming step and an optical functional layer forming step are performed in the chamber 31 of the sputtering apparatus 1. Specifically, the film-forming roll 25 and the guide roll 22 are rotated, the transparent substrate 11 formed with the hard coat 12 is conveyed at a predetermined conveying speed, and an adhesion layer 13 and an optical functional layer 14 are formed on the hard coat 12 moving on the film-forming roll 25.

[0188] In the present embodiment, by changing the material of the target provided in each film-forming unit 41 or the type and flow rate of the reactive gas supplied from the gas supply unit and performing sputtering, the adhesion layer 13 is formed, and the high refractive index layer 14a and the low refractive index layer 14b are alternately laminated thereon. That is, the adhesion layer forming step and the optical functional layer forming step are continuously performed in the sputtering apparatus 1. Thus, the adhesion layer 13 and the optical functional layer 14 as an antireflection layer are formed.

[0189] When forming the SiO x film as the adhesion layer 13, it is preferable to use a silicon target and form it by reactive sputtering using a mixed gas atmosphere of oxygen and argon.

[0190] When continuously laminating the adhesion layer 13, the high refractive index layer 14a, and the low refractive index layer 14b by sputtering, the material of the target can also be changed during the film formation of the adhesion layer 13, the high refractive index layer 14a, and the low refractive index layer 14b. In addition, for example, one material can be used as the target, and by changing the oxygen (reactive gas) flow rate during sputtering, layers composed of the target material and layers composed of the oxide of the target material are alternately formed, thereby forming the adhesion layer 13, the high refractive index layer 14a, and the low refractive index layer 14b.

[0191] The pressure during sputtering for forming the adhesion layer 13 and the optical functional layer 14 varies depending on the sputtered metal, and can be 2 Pa or less, preferably 1 Pa or less, more preferably 0.6 Pa or less, and particularly preferably 0.2 Pa or less. When the pressure during sputtering is in a reduced-pressure state of 1 Pa or less, the mean free path of the film-forming molecules becomes longer, and the film-forming molecules are stacked while maintaining a relatively high energy state, resulting in a dense and better film quality.

[0192] After that, by the rotation of the film-forming roller 25 and the guide roller 22, the transparent substrate 11 having the adhesion layer 13 and the optical functional layer 14 formed thereon is sent out to the pretreatment device 2B.

[0193] Next, in the chamber 32 of the pretreatment device 2B, as a pretreatment for the surface of the antifouling layer 15 to be formed, a second surface treatment process is performed. In the present embodiment, the second surface treatment process is continuously performed while maintaining the reduced-pressure state without allowing the transparent substrate 11 having the optical functional layer 14 formed thereon obtained through the optical functional layer forming process to come into contact with the atmosphere.

[0194] In the second surface treatment process, the can-shaped roller 26 and the guide roller 22 are rotated, and while the transparent substrate 11 having the respective layers up to the optical functional layer 14 formed thereon is conveyed at a predetermined conveying speed, the surface of the optical functional layer 14 moving on the can-shaped roller 26 is subjected to a discharge treatment.

[0195] As a surface treatment method for the optical functional layer 14, for example, glow discharge treatment, plasma treatment, ion etching, alkali treatment, etc. can be used. Among them, glow discharge treatment is preferably used because large-area treatment can be performed.

[0196] When the surface of the optical functional layer 14 is subjected to a discharge treatment, the surface of the optical functional layer 14 is etched, and the surface roughness of the optical functional layer 14 changes. The surface roughness Ra of the optical functional layer 14 can be controlled by setting the cumulative output during the discharge treatment within an appropriate range. In the present embodiment, the cumulative output refers to the value obtained by dividing the product of the glow discharge output irradiated on the optical functional layer 14 and the irradiation time during the discharge treatment by the unit area.

[0197] The conditions of the discharge treatment can be set appropriately. By appropriately setting the conditions of the discharge treatment, the adhesion between the optical functional layer 14 and the antifouling layer 15 formed thereon becomes good, and an optical laminate 10 with better abrasion resistance and alkali resistance can be obtained.

[0198] The surface roughness Ra of the optical functional layer 14 after the discharge treatment varies depending on the surface roughness of the hard coat 12 provided under the optical functional layer 14.

[0199] In addition, the surface roughness Ra of the optical functional layer 14 after the discharge treatment affects the surface roughness Ra of the antifouling layer 15 formed on the optical functional layer 14.

[0200] In the second surface treatment step, the surface of the optical functional layer is treated such that the change rate of the surface roughness represented by the following (Equation 1) becomes 1 to 25%.

[0201] Change rate of surface roughness (%) = ((Ra2 / Ra1) - 1) × 100 (%) ··· Equation (1)

[0202] (In Equation (1), Ra1 represents the surface roughness (Ra) of the optical functional layer before treating the surface, and Ra2 represents the surface roughness (Ra) of the optical functional layer after treating the surface).

[0203] The second surface treatment step is preferably performed such that the change rate of the surface roughness represented by (Equation 1) becomes 5% to 25%, more preferably such that it becomes 8% to 25%, further preferably such that it becomes 8% to 20%, still further preferably such that it becomes 8% to 15%, and even more preferably such that it becomes 10% to 14%. If the change rate of the surface roughness represented by Equation (1) is 1% or more, the effect of improving the adhesion between the optical functional layer 14 and the antifouling layer 15 brought about by performing the second surface treatment step becomes significant. In addition, if the change rate of the surface roughness represented by (Equation 1) is 25% or less, the thickness of the optical functional layer 14 is appropriate, and thus an antifouling layer 15 with a uniform thickness is formed on the optical functional layer 14.

[0204] In the present embodiment, the surface roughness Ra of the optical functional layer 14 can be measured by the method shown below. Using an atomic force microscope (AFM: Atomic Force Microscope), the surface roughness Ra within an area of 1 μm 2 of the surface of the optical functional layer 14 is measured.

[0205] After that, through the rotation of the can-shaped roller 26 and the guide roller 22, the transparent substrate 11 whose surface of the optical functional layer 14 has been treated is sent out to the evaporation apparatus 3.

[0206] Next, an antifouling layer formation process is performed inside the chamber 33 of the vapor deposition apparatus 3. In the present embodiment, the antifouling layer formation process is continuously performed while maintaining a reduced pressure state without allowing the surface of the transparent substrate 11 on which the surface of the optical functional layer 14 obtained through the second surface treatment process has been treated to come into contact with the atmosphere. In the antifouling layer formation process, the guide roller 22 is rotated to convey the transparent substrate 11 on which the surface of the optical functional layer 14 has been treated at a prescribed conveyance speed, and the vapor deposition source 43 is vapor-deposited on the surface of the optical functional layer 14.

[0207] In the present embodiment, for example, the antifouling material composed of a fluorine-based organic compound for forming the antifouling layer 15 is heated to the vapor pressure temperature by the heating device 53, and the resulting evaporation gas is supplied from the vapor deposition source 43 in a reduced pressure environment and made to adhere to the surface-treated optical functional layer 14, and the antifouling layer 15 is formed by vacuum vapor deposition.

[0208] The pressure during the vacuum vapor deposition of the antifouling layer 15 is preferably, for example, 0.05 Pa or less, more preferably 0.01 Pa or less, and particularly preferably 0.001 Pa or less. When the pressure during the vacuum vapor deposition is in a reduced pressure state of 0.05 Pa or less, the mean free path of the film-forming molecules is long and the vapor deposition energy is high, so a dense and better antifouling layer 15 can be obtained.

[0209] Through the above method, an optical laminate 10 is obtained in which an antifouling layer 15 is formed by vacuum vapor deposition on the adhesion layer 13 and the optical functional layer 14 formed by sputtering.

[0210] Then, by the rotation of the guide roller 22, the transparent substrate 11 (optical laminate 10) on which the layers up to the antifouling layer 15 are formed is sent out to the roll winding device 5.

[0211] Then, inside the chamber 35 of the roll winding device 5, the optical laminate 10 is wound around the winding roll 24 by the rotation of the winding roll 24 and the guide roller 22.

[0212] In the present embodiment, it is preferable to continuously perform the optical functional layer formation process and the antifouling layer formation process under reduced pressure. In particular, as used Figure 4In the case where the optical laminate 10 is continuously manufactured into a wound body in a roll-to-roll manner as in the manufacturing method of the present embodiment of the manufacturing apparatus 20 shown, it is more preferable to continuously perform the optical functional layer forming step and the antifouling layer forming step online while maintaining a reduced pressure state. Online means performing the antifouling layer forming step without bringing the optical functional layer 14 formed in the optical functional layer forming step into contact with the atmosphere. By continuously performing the optical functional layer forming step and the antifouling layer forming step under reduced pressure, before forming the antifouling layer 15, generation of a natural oxide film on the optical functional layer 14 formed in the optical functional layer forming step can be suppressed. In addition, it is possible to prevent contaminants such as foreign matter from adhering to the optical functional layer 14 when winding the roll, which may hinder the adhesion between the optical functional layer 14 and the antifouling layer 15. Therefore, compared with the case where the transparent substrate 11 having layers up to the optical functional layer 14 formed thereon is taken out from the chamber in a reduced pressure state after the optical functional layer forming step, and then is set again in the chamber and the antifouling layer forming step is performed under reduced pressure, an optical laminate having good adhesion between the optical functional layer 14 and the antifouling layer 15 and excellent transparency can be obtained.

[0213] In addition, the antifouling layer 15 of the optical laminate 10 of the present embodiment is a vapor deposition film, and thus high abrasion resistance can be obtained compared with, for example, an antifouling film formed by a coating method. It is presumed that this is due to the following reasons. That is, in the antifouling film formed by the coating method, voids are present due to the solvent contained in the coating material. In contrast, in the vapor deposition film, there are no voids caused by the solvent. Therefore, it is presumed that the vapor deposition film is denser than the antifouling film formed by the coating method and can obtain high abrasion resistance and alkali resistance.

[0214] The manufacturing method of the optical laminate 10 of the present embodiment includes: a bonding layer forming step of forming a bonding layer 13; an optical functional layer forming step of forming an optical functional layer 14 by alternately laminating a high refractive index layer 14a and a low refractive index layer 14b; a second surface treatment step of treating the surface of the optical functional layer 14; and an antifouling layer forming step of forming an antifouling layer 15 on the surface-treated optical functional layer 14. Therefore, the adhesion between the optical functional layer 14 and the antifouling layer 15 formed on the optical functional layer 14 is good, and a layer having better frictional properties and alkali resistance is obtained.

[0215] In particular, in the second surface treatment step, when the surface of the optical functional layer is treated so that the change rate of the surface roughness represented by (Equation 1) becomes 1 to 25%, the surface of the optical functional layer 14 changes to an appropriate roughness, and the surface can be activated by etching. Therefore, the reactivity with the antifouling layer 15 formed on the optical functional layer 14 is improved, and thus it is preferable.

[0216] In addition, in the method for manufacturing the optical laminate 10 of the present embodiment, since the optical laminate 10 can be continuously formed in a roll-to-roll manner and the film thickness can be controlled with high precision, in the optical functional layer forming step, it is preferable to form the optical functional layer 14 by sputtering.

[0217] In the present embodiment, when the optical laminate during manufacturing is maintained under reduced pressure and the first surface treatment step, the optical functional layer forming step, the second surface treatment step, and the antifouling layer forming step are continuously performed, as long as it is within a range that does not hinder each manufacturing step, for example, in a sputtering apparatus and an evaporation apparatus, the reduced pressure conditions in the chamber can be different.

[0218] In the present embodiment, it is preferable to measure the film formation result with a measuring instrument over time in any one or more of the adhesion layer forming step, the optical functional layer forming step, and the antifouling layer forming step, and feed back the result to the conditions of the manufacturing steps corresponding to the subsequent steps. Thereby, it is easy to optimize the characteristics of the entire optical laminate, and the in-plane characteristics of the optical laminate can be made uniform. In addition, the measuring instrument can also be used to feed back the manufacturing conditions in the same step. In this case, the layer formed in this step has uniform and stable characteristics.

[0219] In the present embodiment, the case where the second surface treatment step is performed between the optical functional layer forming step and the antifouling layer forming step has been described as an example, but the second surface treatment step can be performed as needed or may not be performed. Even when the second surface treatment step is not performed, it is preferable to continuously perform the optical functional layer forming step and the antifouling layer forming step under reduced pressure.

[0220] In the present embodiment, the manufacturing apparatus 20 shown in Figure 4 which includes the pretreatment apparatus 2A, the sputtering apparatus 1, the pretreatment apparatus 2B, the evaporation apparatus 3, the roll unwinding apparatus 4, and the roll winding apparatus 5 has been described as an example of continuously manufacturing the optical laminate 10 in a roll-to-roll manner, but the manufacturing apparatus for manufacturing the optical laminate 10 is not limited to Figure 4 the manufacturing apparatus 20 shown.

[0221] For example, the pretreatment apparatus 2A and the pretreatment apparatus 2B may not be included, and a manufacturing apparatus in which the roll unwinding apparatus 4, the sputtering apparatus 1, the evaporation apparatus 3, and the roll winding apparatus 5 are connected in sequence may be used.

[0222] In Figure 4 the manufacturing apparatus 20 shown, a pretreatment chamber (not shown) for cleaning the surface of the optical functional layer 14 for forming the antifouling layer 15 may also be provided between the chamber 33 of the evaporation apparatus 3 and the chamber 32 of the pretreatment apparatus 2B.

[0223] exist Figure 4 In the manufacturing apparatus 20 shown, a post-processing chamber (not shown) for cooling and / or inspecting the transparent substrate 11 formed with each layer up to the antifouling layer 15 may be provided between the chamber 33 of the vapor deposition device 3 and the chamber 35 of the roll winding device 5 .

[0224] exist Figure 4 In the manufacturing apparatus 20 shown, a hard coating forming device for forming a hard coating layer 12 on the surface of the transparent substrate 11 may be provided between the roll unwinding device 4 and the sputtering device 1. In this case, not only the optical functional layer 14 and the antifouling layer 15 but also the hard coating layer 12 can be continuously manufactured in a roll-to-roll manner, which is preferred.

[0225] In this embodiment, the case where a sputtering device is used to perform the optical functional layer forming process and a vapor deposition device is used to perform the anti-fouling layer forming process is described as an example, but the optical functional layer forming process and the anti-fouling layer forming process can also be performed in the same device (in one chamber) without performing the second surface treatment process.

[0226] In the optical laminate 10 of the present embodiment, various layers can be provided on the surface of the transparent substrate opposite to the surface on which the optical functional layer is formed as needed. For example, an adhesive layer for bonding to other components can also be provided. In addition, other optical films can also be provided across the adhesive layer. As other optical films, for example, polarizing films, phase difference compensation films, films that function as 1 / 2 wavelength plates and 1 / 4 wavelength plates, etc. can be cited.

[0227] In addition, a layer having functions such as anti-reflection, selective reflection, anti-glare, polarization, phase difference compensation, viewing angle compensation or magnification, light guiding, diffusion, brightness enhancement, hue adjustment, and conductivity can also be directly formed on the opposite surface of the transparent substrate.

[0228] In addition, the shape of the optical laminate can be a smooth shape, or a shape having a moth-eye or nanometer-level concave-convex structure that embodies an anti-glare function. In addition, it can also be a geometric shape of micrometer to millimeter level such as a lens or a prism. The shape can be formed, for example, by a combination of photolithography and etching, shape transfer, hot pressing, etc. In this embodiment, since film formation is performed by vapor deposition, even when the substrate has, for example, a concave-convex shape, its concave-convex shape can be maintained.

[0229] The article of this embodiment is an article in which the above-mentioned optical laminate 10 is provided on the display surface of the image display part such as a liquid crystal display panel, an organic EL display panel, etc. Thus, for example, the touch panel display part of a smart phone or an operating device can be given high wear resistance and alkali resistance, and an image display device with excellent durability and suitable for practical use can be realized.

[0230] In addition, the article is not limited to an image display device. For example, as long as it is an article such as a window glass, goggles, a light-receiving surface of a solar cell, a screen of a smartphone, a display of a personal computer, an information input terminal, a tablet terminal, an AR (augmented reality) device, a VR (virtual reality) device, an electro-optical display panel, a surface of a glass table, a game machine, an operation assistance device such as an airplane or a tram, a navigation system, an instrument panel, a surface of an optical sensor, etc. on which the optical laminate 10 of the present embodiment can be applied, it can be any article.

[0231] As described above, the embodiments of the present invention have been described, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and its equivalents.

[0232] For example, an antiglare layer can be formed instead of the hard coat 12, or any functional layer such as a soft coat having flexibility can be added as needed. They can also be laminated.

[0233] Examples

[0234] The effects of the present invention were verified.

[0235] It should be noted that the optical laminates produced in the following examples and comparative examples are an example of functioning as an antireflection film, and the gist of the present invention is not limited to these.

[0236] (Examples 1 to 5, Comparative Example 2)

[0237] First, a photocurable resin composition in which the content of silica particles (filler) having an average particle diameter of 50 nm is 28% by mass based on the total solid content of the resin composition (binder resin) was prepared. As shown in Table 1, the resin composition was prepared by dissolving silica particles, acrylate, a leveling agent, and a photopolymerization initiator in a solvent.

[0238] [Table 1]

[0239]

[0240] SR610: Polyethylene glycol diacrylate, average molecular weight of polyethylene glycol chain 600

[0241] CN968: 6-functional aliphatic urethane acrylate having a polyester backbone

[0242] Irgacure184: 1-Hydroxy-cyclohexyl-phenyl-ketone

[0243] <Hard coat forming process>

[0244] Prepare a roll-shaped TAC film with a thickness of 80 μm and a length of 3900 m as the transparent substrate 11. Coating the TAC film with the photocurable resin composition shown in Table 1 using a gravure coater, irradiating light to cure it, and forming a hard coat 12 with a thickness of 5 μm.

[0245] Next, in a roll-to-roll manner, by the method shown below, a bonding layer 13, an optical functional layer 14, and an antifouling layer 15 are successively and continuously formed on the transparent substrate 11 on which the hard coat 12 is formed, to produce the optical laminates (antireflection films) of Examples 1 to 5 and Comparative Example 2.

[0246] As the manufacturing apparatus, use Figure 4 the manufacturing apparatus 20 shown. In addition, the linear velocity is 2 m / min. The first surface treatment process, the bonding layer forming process, the optical functional layer forming process, the second surface treatment process, and the antifouling layer forming process are continuously carried out while maintaining the optical laminate being manufactured under a reduced pressure state.

[0247] <First surface treatment process>

[0248] Next, for the hard coat 12, set the treatment intensity of the glow discharge treatment to 4000 W·min / m 2 , and carry out the glow discharge treatment.

[0249] <Bonding layer forming process and optical functional layer forming process>

[0250] On the hard coat 12 after the glow discharge treatment, in a chamber under a pressure of 1.0 Pa or less, a bonding layer 13 made of SiOx with a thickness of 5 nm is formed by sputtering, and an optical functional layer 14 (laminate) composed of a Nb 2 O 5 film (high refractive index layer) with a thickness of 15 nm, a SiO 2 film (low refractive index layer) with a thickness of 38 nm, a Nb 2 O 5 film (high refractive index layer) with a thickness of 30 nm, and a SiO 2 film (low refractive index layer) with a thickness of 102 nm is formed on the bonding layer.

[0251] <Second surface treatment process>

[0252] The surface of the optical functional layer 14 is subjected to glow discharge treatment. The cumulative output of the glow discharge treatment is shown in Table 2. The relative values (output relative values) are shown in Table 2 when the cumulative output of the glow discharge treatment in Example 1 is set to 100. Regarding Example 1, the cumulative output of the glow discharge treatment is set to 326 W·min / m 2 is carried out.

[0253] In addition, the change rate of the surface roughness represented by the following (Formula 1) is shown in Table 2.

[0254] Change rate of surface roughness (%) = ((Ra2 / Ra1) - 1) × 100 (%) ··· Formula (1)

[0255] (In Formula (1), Ra1 represents the surface roughness (Ra) of the optical functional layer before surface treatment, and Ra2 represents the surface roughness (Ra) of the optical functional layer after surface treatment).

[0256] <Antifouling layer forming step>

[0257] Next, on the optical functional layer 14, an antifouling layer 15 composed of an alkoxysilane compound (KY-1901, manufactured by Shin-Etsu Chemical Co., Ltd.) having a perfluoropolyether group as a fluorine-containing organic compound is formed by vapor deposition at a chamber pressure of 0.01 Pa or less, a vapor deposition temperature of 230°C, and a linear velocity of 2.0 m / min. The optical film thickness of the obtained antifouling layer 15 is shown in Table 2.

[0258] Thereafter, it is wound into a roll shape to obtain the optical laminates (antireflection films) of Examples 1 to 5 and Comparative Example 2.

[0259] [Table 2]

[0260]

[0261] (Comparative Example 1)

[0262] After carrying out up to the optical functional layer forming step in the same manner as in Example 1, the antifouling layer forming step is carried out without performing the surface treatment step, and the antifouling layer 15 is formed on the optical functional layer 14. Except for this, the operation is the same as in Example 1 to produce the optical laminate (antireflection film) of Comparative Example 1.

[0263] (Comparative Example 3)

[0264] After proceeding to the optical functional layer formation step in the same manner as in Example 1, the TAC film formed with the hard coat layer 12, the adhesion layer 13, and the optical functional layer 14 was wound up, taken out from the manufacturing apparatus, and set in a roll-to-roll type coating apparatus (coater). Then, under atmospheric pressure, the TAC film formed with the hard coat layer 12, the adhesion layer 13, and the optical functional layer 14 was unwound, and an antifouling agent was coated on the SiO 2 film (low refractive index layer) of the optical functional layer 14 at a linear speed of 20 m / min using a gravure coater.

[0265] As the antifouling agent, an antifouling agent in which an alkoxysilane compound having a perfluoropolyether group (KY-1901, manufactured by Shin-Etsu Chemical Co., Ltd.) was diluted to a concentration of 0.1 mass% using a fluorine solvent (Fluorinert FC-3283: manufactured by 3M Japan Ltd.) was used. The antifouling agent was coated so that the thickness after drying was the film thickness shown in Table 2.

[0266] For the obtained optical laminates (antireflection films) of Examples 1 to 5 and Comparative Examples 1 to 3, the surface roughness Ra of the antifouling layer was investigated by the methods shown below. The results are shown in Table 2.

[0267] (Measurement of the surface roughness Ra of the antifouling layer)

[0268] A 50 mm × 50 mm measurement sample was cut out from the position at the center in the length direction and the center in the roll width direction of each roll on which the optical laminate was wound up. The surface of the sample was observed using an atomic force microscope (AFM: Atomic Force Microscope) (trade name SPA 400, NanoNaviII; manufactured by Hitachi, Ltd.), and the surface roughness Ra in a range of an area of 1 μm 2 was measured.

[0269] The surface roughness Ra of the antifouling layer is affected by the surface roughness Ra of the optical functional layer below it. In particular, in the antifouling layer formed by vapor deposition, there are no voids caused by the solvent contained in the coating material as in the antifouling layer formed by the coating method, but it is formed densely. Therefore, compared with the antifouling layer formed by the coating method, the influence of the surface roughness Ra of the optical functional layer below it is large. When the surface of the optical functional layer is subjected to glow discharge treatment, the surface roughness becomes larger, and as a result, the surface roughness of the antifouling layer becomes larger. In addition, when the optical functional layer is in contact with the atmosphere, a natural oxide film is formed on the optical functional layer, and the surface roughening effect based on the glow discharge treatment becomes smaller. On the other hand, when the optical functional layer and the antifouling layer are formed without being in contact with the atmosphere, they are not affected in this way. In addition, the difference in surface roughness between Example 1 and Comparative Example 1 is due to the presence or absence of glow discharge treatment.

[0270] In addition, the properties of the optical laminates (antireflection films) of Examples 1 to 5 and Comparative Examples 1 to 3 were investigated respectively. The results are shown in Tables 2 to 4. The test pieces used in the property measurements of Examples 1 to 5 and Comparative Examples 1 and 2 were cut out from near the approximate center in the length direction of the roll on which the optical laminate was wound.

[0271] [Table 3]

[0272]

[0273] [Table 4]

[0274]

[0275] (1) Contact angle (antifouling property)

[0276] (1-1) Contact angle measurement test for pure water

[0277] Using a fully automatic contact angle meter DM-700 (manufactured by Kyowa Interface Science Co., Ltd.), the measurement was carried out by the ellipse fitting method under the following conditions. Distilled water was put into a glass syringe, and a stainless steel needle was attached to the front end thereof, and pure water was dropped onto the optical laminates (test pieces) of Examples 1 to 5 and Comparative Examples 1 and 2.

[0278] Drop volume of pure water: 2.0 μL

[0279] Measurement temperature: 25 °C

[0280] The contact angle 4 seconds after dropping pure water was measured at any 6 places on the surface of the test piece, and the average value thereof was taken as the pure water contact angle.

[0281] (1-2) Contact angle measurement test for oleic acid, n-hexadecane, and diiodomethane (reagents)

[0282] Using a fully automatic contact angle meter DM-700 (manufactured by Kyowa Interface Science Co., Ltd.), the measurement was carried out by the ellipse fitting method under the following conditions. Each of the above reagents was put into a glass syringe, and a stainless steel needle was attached to the front end thereof, and each reagent was dropped onto the optical laminate (test piece) of Example 1.

[0283] Drop volume of each reagent: 2.0 μL

[0284] Measurement temperature: 25 °C

[0285] The contact angle 4 seconds after dropping each reagent was measured at any 10 places on the surface of the test piece, and the average value thereof was taken as the contact angle of oleic acid, n-hexadecane, and diiodomethane, respectively.

[0286] (2) Fluorine content measurement test

[0287] Measure the fluorine content (cps: counts per unit time) of the optical laminates (test pieces) of Examples 1 to 5 and Comparative Examples 1 to 3 (fluorine content before cleaning (fluorine content in the initial state)).

[0288] In the measurement of the fluorine content, an X-ray photoelectron spectrometer (Electron Spectroscopy for Chemical Analysis (ESCA)) (PHI5000 VersaProb*eIII, manufactured by ULVAC-PHI, Inc.) and X-ray fluorescence analysis (XRF) (EDX-8000, manufactured by Shimadzu Corporation) were used. The fluorine values (cps) obtained by the X-ray photoelectron spectrometer and X-ray fluorescence analysis were average values calculated based on the results measured with n = 3 in the initial state and n = 15 after the alkali resistance test.

[0289] (3) Alkali resistance test

[0290] Measure the optical properties of the optical laminates (test pieces) of Examples 1 to 5 and Comparative Examples 1 to 3 (samples before treatment).

[0291] Next, prepare an aqueous sodium hydroxide solution (reagent) with a concentration of 0.1 mol / L.

[0292] Then, a cylindrical member with an inner diameter of 38 mm was closely attached to the optical laminates (test pieces) of Examples 1 to 5 and Comparative Examples 1 to 2, the reagent was dropped into it, and the upper surface opening was covered with a glass plate and covered with a lid. Then, after maintaining the liquid temperature at 55 °C and standing for 4 hours, each test piece was washed with distilled water to obtain a sample after treatment.

[0293] (3-1) Optical property measurement (hue change)

[0294] The backs of the above samples before treatment and after treatment were pasted to a black acrylic plate with transparent tape to eliminate back reflection. Then, the optical properties were measured.

[0295] An integrating sphere spectrophotometer (SP-64: manufactured by X-rite, Inc.) was used for optical measurement. It was set to a D65 light source and 10°, and the change amount, i.e., the ΔE value, of the L*a*b* (based on CIE1976) values shown in the above formula (2) of the samples before treatment and after treatment based on SCI (Specular Component Include, a measurement method considering the reflected color of the specularly reflected light) was calculated.

[0296] (3-2) Fluorine residue measurement test using an alkali solution

[0297] In the same manner as the test in (2) above, the fluorine amount (cps) of the sample after treatment with the alkali solution was measured using ESCA or XRF, and the residual ratio (%) of fluorine in the treated sample was calculated.

[0298] (4) Abrasion resistance test using steel wool

[0299] Using the friction tester type I according to JIS L0849, the friction body was horizontally reciprocated along the surface of the optical laminate (test piece) of Example 1 to obtain a test piece.

[0300] As the friction body, steel wool (No. 0000, manufactured by Bonstar Co., Ltd.) was used. The test was set with a load of 1000 g / cm 2 , a stroke of 75 mm, and a speed of 7 mm / s. The number of horizontal reciprocations of the friction body is shown in Table 4.

[0301] (4-1) Contact angle

[0302] In the same manner as the test in (1-1) above, the contact angle of the test piece after friction was measured, and the difference in contact angle between the test piece before friction and after 500 horizontal reciprocations was obtained. The test was carried out within 30 minutes after friction.

[0303] (4-2) Optical property measurement (hue change)

[0304] In the same manner as the test in (3-1) above, the ΔL * a * b * value change, that is, the ΔE value, of the test piece before friction and after 500 horizontal reciprocations was calculated based on SCI.

[0305] In addition, in the same manner as the test in (3-1) above, the L * a * b * value change, that is, the ΔE value, shown in the above formula (3) of the test piece before friction and after 500 horizontal reciprocations was calculated based on SCE (Specular Component Exclude, a measurement method that does not consider the reflected color of the specularly reflected light).

[0306] (5) Abrasion resistance test using a piece of cloth (non-woven wipe)

[0307] An abrasion resistance test was carried out in the same manner as the abrasion resistance test using steel wool, except that a piece of cloth (non-woven wipe) (BEMCOT LINT FREE CT-8, manufactured by Asahi Kasei Corporation) was used as the friction body. The test was set with a load of 250 g / cm 2, Stroke: 25 mm, speed: 50 mm / s. The number of horizontal reciprocating motions of the friction body is shown in Table 3.

[0308] (5-1) Contact angle

[0309] In the same way as the test in (1-1) above, measure the contact angle of the test piece after friction, and find the difference in the contact angle of the test piece before friction and after 4000 horizontal reciprocating motions. The test is carried out within 30 minutes after friction.

[0310] (5-2) Fluorine residue measurement test

[0311] Operate in the same way as the test in (2) above. Use ESCA to measure the fluorine content (cps) of the treated sample after 4000 horizontal reciprocating motions with a cloth head, and calculate the residual rate (%) of fluorine in the treated sample.

[0312] As can be confirmed from Tables 2 to 4, the optical laminates of Examples 1 to 5, which have a surface treatment step of treating the surface of the optical functional layer 14 and an antifouling layer forming step of forming an antifouling layer 15 on the surface-treated optical functional layer 14, have a higher fluorine residue rate in the alkali resistance test, a smaller hue change ΔE of 5 or less, and good alkali resistance compared with Comparative Example 1 in which the surface treatment step was not carried out.

[0313] In addition, the optical laminates of Examples 1 to 5 have a smaller contact angle difference of 14 or less and a higher fluorine residue rate in the abrasion resistance test using a cloth head (non-woven fabric wiper) compared with Comparative Examples 1 and 2.

[0314] The optical laminates of Examples 1 to 5 have a smaller hue change and a higher fluorine residue rate in the alkali resistance test compared with Comparative Examples 1 and 2.

[0315] The optical laminates of Examples 1 to 5 have a smaller contact angle difference of 14 or less in the abrasion resistance test using a cloth head (non-woven fabric wiper) compared with Comparative Example 3, and also have a smaller hue change and a higher fluorine residue rate in the alkali resistance test.

[0316] Symbol description

[0317] 10, 101, 102... Optical laminate

[0318] 11... Transparent substrate

[0319] 12... Hard coat

[0320] 13... Adhesive layer

[0321] 14... Optical functional layer

[0322] 14a... High refractive index layer

[0323] 14b…Low refractive index layer

[0324] 15…Anti-fouling layer

[0325] 20…Manufacturing device

[0326] 1…Sputtering device

[0327] 2A, 2B…Pretreatment device

[0328] 3…Evaporation device

[0329] 4…Roll unwinding device

[0330] 5…Roll winding device

[0331] 20…Manufacturing device

[0332] 21…Vacuum pump

[0333] 22…Guide roller

[0334] 23…Unwinding roller

[0335] 24…Winding roller

[0336] 25…Film-forming roller

[0337] 26…Tank-shaped roller

[0338] 31, 32, 33, 34, 35…Chamber

[0339] 41…Film-forming part

[0340] 42…Plasma discharge device

[0341] 43…Evaporation source

[0342] 53…Heating device.

Claims

1. A method for manufacturing an optical laminate, which is a method for manufacturing an optical laminate formed by sequentially laminating a transparent substrate as a plastic film, a hard coat layer, an adhesion layer, an optical functional layer, and an antifouling layer, wherein the surface roughness Ra of the antifouling layer is 3 nm or more and 9 nm or less, and the optical thickness of the antifouling layer is 3 nm or more and 10 nm or less. Comprising: A hard coat layer forming step of forming a hard coat layer; An adhesion layer forming step of forming an adhesion layer; An optical functional layer forming step of forming an optical functional layer; A surface treatment step of treating the surface of the optical functional layer; And An antifouling layer forming step of forming an antifouling layer on the surface-treated optical functional layer, The hard coat layer is composed of a cured product of an adhesive resin and a curable resin composition containing silica particles with an average particle size of 100 nm or less. The thickness of the adhesion layer is 1 nm or more and 10 nm or less. The antifouling layer is composed of a vapor deposition film formed by vapor-depositing an alkoxysilane compound having a perfluoropolyether group. The surface treatment in the surface treatment process is glow discharge treatment, and the cumulative output of the glow discharge treatment is 100 or more and 333 or less in terms of the relative value when 2 is set to 100, with the unit of W·min / m. 2 is set to 100.

2. The method for manufacturing an optical laminate according to claim 1, wherein, In the adhesion layer forming step and the optical functional layer forming step, the adhesion layer and the optical functional layer are formed by sputtering.

3. The method for manufacturing an optical laminate according to claim 1, characterized in that, The adhesion layer forming step, the optical functional layer forming step, the surface treatment step, and the antifouling layer forming step are continuously performed under reduced pressure.

4. The method for manufacturing an optical laminate according to claim 1, wherein, The optical functional layer is any one selected from an antireflection layer, a selective reflection layer, and an antiglare layer.

5. The method for manufacturing an optical laminate according to claim 1, wherein, The optical functional layer includes a low refractive index layer.

6. The method for manufacturing an optical laminate according to claim 1, wherein, The optical functional layer forming step is a step of alternately laminating a low refractive index layer and a high refractive index layer to form a laminate.

7. The method for manufacturing an optical laminate according to claim 6, wherein, In the surface treatment step, the surface of the low refractive index layer is treated.

8. The method for manufacturing an optical laminate according to claim 6, wherein, The low refractive index layer contains an oxide of Si.

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